Display panel, and display device including the same

ABSTRACT

A display panel including a glass substrate having an opening area, and a display area at least partially surrounding the opening area; a thin film transistor on the display area including a semiconductor layer and a gate electrode; a display element electrically connected to the thin film transistor; a multi-layer including an insulating layer and a lower insulating layer. The insulating layer is between the glass substrate and the display element and the lower insulating layer is between the glass substrate and the insulating layer; and a thin-film encapsulation layer covering the display element including an inorganic encapsulation layer and an organic encapsulation layer. The multi-layer includes a first groove between the opening area and the display area. A first width of a portion of the first groove in the lower insulating layer is greater than a second width of a portion of the first groove in the insulating layer.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2018-0109179, filed on Sep. 12, 2018, in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein in its entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to a display panel and a display deviceincluding the display panel.

2. Description of the Related Art

Related art display devices have a diverse range of uses. Additionally,due to their relatively small thickness and light weight, their range ofapplications has also increased.

While a display area of a display device has increased, variousfunctions connected or linked to the display device have been added tothe display device. As a method of adding various functions whileincreasing the display area, a display device in which an area connectedor linked to the functions is formed in the display area has beendeveloped.

SUMMARY

In a display device including an opening, a layer(s) including anorganic material and exposed via a lateral surface of the openingprovides a moisture-infiltrating path, and thus display elements that atleast partially surround the opening may be damaged.

One or more embodiments include a display panel capable of preventinginfiltration of moisture via an opening of the display panel, and adisplay device including the display panel. However, the one or moreembodiments are only examples, and the scope of the present invention isnot limited thereto.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to one or more embodiments, a display panel includes a glasssubstrate including an opening area, and a display area at leastpartially surrounding the opening area; a thin film transistor on thedisplay area and including a semiconductor layer and a gate electrode; adisplay element electrically connected to the thin film transistor; amulti-layer including at least one insulating layer and a lowerinsulating layer, wherein the at least one insulating layer is betweenthe glass substrate and the display element and the lower insulatinglayer is between the glass substrate and the at least one insulatinglayer; and a thin-film encapsulation layer covering the display elementand including at least one inorganic encapsulation layer and at leastone organic encapsulation layer, wherein the multi-layer includes afirst groove located between the opening area and the display area, anda first width of a portion of the first groove in the lower insulatinglayer is greater than a second width of a portion of the first groove inthe at least one insulating layer.

A bottom surface of the first groove may be on a virtual surface inbetween an upper surface of the lower insulating layer and an uppersurface of the glass substrate or on a same virtual surface as the uppersurface of the glass substrate.

The at least one insulating layer may include a first hole correspondingto the first groove, and the lower insulating layer may include a secondhole or recess corresponding to the first groove.

A lateral surface of the at least one insulating layer facing a centerof the first groove is closer to the center of the first groove than alateral surface of the lower insulating layer facing the center of thefirst groove. The lower insulating layer may be in direct contact withan upper surface of the glass substrate.

The at least one inorganic encapsulation layer may cover an innersurface of the first groove.

A portion of the at least one inorganic encapsulation layer may be indirect contact with a portion of the glass substrate within the firstgroove.

The glass substrate may include a first opening corresponding to theopening area.

An end of the glass substrate that defines the first opening i closer toa center of the opening area than an end of the lower insulating layerfacing the opening area.

The multi-layer may further include a second groove between the firstgroove and the opening area.

An end of the at least one organic encapsulation layer may be betweenthe first groove and the second groove.

The display panel may further include a partition wall on themulti-layer and located between the first groove and the second groove.

The lower insulating layer may include an organic insulating layer andthe at least one insulating layer may include an inorganic insulatinglayer.

The lower insulating layer may include at least one of silicon nitrideand silicon oxycarbide, and the at least one insulating layer mayinclude an inorganic insulating layer that includes a different materialfrom the lower insulating layer.

According to one or more embodiments, a display device includes asubstrate including an opening; a thin film transistor on a display areaof the substrate, the display area at least partially surrounding theopening, and including a semiconductor layer and a gate electrode; adisplay element electrically connected to the thin film transistor; amulti-layer including a lower insulating layer and at least oneinsulating layer, wherein the lower insulating layer is located on thesubstrate and the at least one insulating layer is located on the lowerinsulating layer and includes a different material from the lowerinsulating layer; and an encapsulation layer configured to cover thedisplay element, wherein the multi-layer includes a first groove that isconcave in a depth direction of the multi-layer, and a width of aportion of the first groove in the lower insulating layer is greaterthan a width of a portion of the first groove in the at least oneinsulating layer.

The substrate may include a glass material, a polymer material, or ametal material.

A bottom surface of the first groove may be on a virtual surface inbetween an upper surface of the lower insulating layer and an uppersurface of the substrate or on a same virtual surface as the uppersurface of the substrate.

The at least one insulating layer may include a first hole correspondingto the first groove, and the lower insulating layer may include a secondhole or recess corresponding to the first groove.

The at least one insulating layer may include an inorganic insulatinglayer.

The lower insulating layer may include an organic insulating layer ormay include an inorganic insulating layer that is different from the atleast one insulating layer.

A lateral surface of the at least one insulating layer directed toward acenter of the first groove may protrude farther than a lateral surfaceof the lower insulating layer directed toward the center of the firstgroove.

An end of the substrate directed toward the opening may protrude towardthe opening farther than an end of the lower insulating layer directedtoward the opening.

The multi-layer may further include a second groove between the firstgroove and the opening.

The encapsulation layer may include at least one inorganic encapsulationlayer and at least one organic encapsulation layer, and the at least oneinorganic encapsulation layer may cover an inner surface of each of thefirst groove and the second groove.

A portion of the at least one organic encapsulation layer may at leastpartially fill the first groove.

The display device may further include a partition wall on themulti-layer and located between the first groove and the second groove.

The at least one inorganic encapsulation layer may be in direct contactwith an upper surface of the substrate within the first groove or thesecond groove.

The at least one insulating layer may include a first insulating layerand a second insulating layer on the first insulating layer, the firstand second insulating layers including different materials. The firstinsulating layer and the second insulating layer may include holescorresponding to the first groove, respectively, and a width of the holeof the second insulating layer may be less than a width of the hole ofthe first insulating layer.

The display element may include an organic light-emitting diode.

At least one of an organic layer and an opposite electrode included inthe organic light-emitting diode may be disconnected by the firstgroove.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a schematic perspective view of a display device according toan embodiment;

FIGS. 2A through 2D are schematic cross-sectional views of the displaydevice according to embodiments;

FIG. 3 is a schematic plan view of a display panel according to anembodiment;

FIG. 4 is a circuit diagram of one of a plurality of pixels of thedisplay panel;

FIG. 5 is a plan view of a portion of a display panel according to anembodiment showing signal lines located in a first non-display area;

FIG. 6 is a plan view of a portion of a display panel according to anembodiment showing grooves located in a first non-display area;

FIG. 7 is a cross-sectional view of the display panel of FIG. 6;

FIG. 8 is a magnified cross-sectional view of an organic light-emittingdisplay diode according to an embodiment;

FIG. 9A is a cross-sectional view of a first groove according to anembodiment, and FIG. 9B is a cross-sectional view illustrating a stackedstructure on the first groove of FIG. 9A;

FIG. 10A is a cross-sectional view of a first groove according toanother embodiment, and FIG. 10B is a cross-sectional view illustratinga stacked structure on the first groove of FIG. 10A;

FIG. 11 is a cross-sectional view of a display panel according toanother embodiment;

FIG. 12A is a cross-sectional view of a first groove according toanother embodiment, and FIG. 12B is a cross-sectional view illustratinga stacked structure on the first groove of FIG. 12A;

FIG. 13 is a cross-sectional view of a display panel according toanother embodiment;

FIG. 14 is a cross-sectional view of a display panel according toanother embodiment;

FIG. 15A is a cross-sectional view of a first groove according toanother embodiment, and FIG. 15B is a cross-sectional view illustratinga stacked structure on the first groove of FIG. 15A;

FIG. 16 is a cross-sectional view of a display panel according toanother embodiment;

FIG. 17 is a cross-sectional view of a display panel according toanother embodiment;

FIG. 18 is a plan view of a display panel according to anotherembodiment;

FIG. 19 is a plan view of surroundings of an opening area according toanother embodiment;

FIG. 20 is a cross-sectional view of the display panel of FIG. 19;

FIG. 21 is a plan view of a display panel according to anotherembodiment;

FIG. 22 is a plan view of surroundings of an opening area according toanother embodiment; and

FIG. 23 is a cross-sectional view of the display panel of FIG. 22.

DETAILED DESCRIPTION

As the disclosure allows for various changes and numerous embodiments,particular embodiments will be illustrated in the drawings and describedin detail in the written description. Hereinafter, effects and featuresof the present disclosure and a method for accomplishing them will bedescribed more fully with reference to the accompanying drawings, inwhich embodiments of the disclosure are shown. This disclosure may,however, be embodied in many different forms and should not be construedas limited to the embodiments set forth herein.

One or more embodiments of the disclosure will be described below inmore detail with reference to the accompanying drawings. Thosecomponents that are the same or are in correspondence are rendered thesame reference numeral regardless of the figure number, and redundantexplanations are omitted.

It will be understood that although the terms “first”, “second”, etc.may be used herein to describe various components, these componentsshould not be limited by these terms. These components are only used todistinguish one component from another.

As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

It will be further understood that the terms “comprises” and/or“comprising” used herein specify the presence of stated features orcomponents, but do not preclude the presence or addition of one or moreother features or components.

It will be understood that when a layer, region, or component isreferred to as being “formed on” another layer, region, or component, itcan be directly or indirectly formed on the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may be present.

Sizes of elements in the drawings may be exaggerated for convenience ofexplanation. In other words, since sizes and thicknesses of componentsin the drawings are arbitrarily illustrated for convenience ofexplanation, the following embodiments are not limited thereto.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

It will also be understood that when a layer, region, or component isreferred to as being “connected” or “coupled” to another layer, region,or component, it can be directly connected or coupled to the otherlayer, region, or component or intervening layers, regions, orcomponents may be present. For example, when a layer, region, orcomponent is referred to as being “electrically connected” or“electrically coupled” to another layer, region, or component, it can bedirectly electrically connected or coupled to the other layer, region,or component or intervening layers, regions, or components may bepresent.

FIG. 1 is a schematic perspective view of a display device 1 accordingto an embodiment of the present disclosure.

Referring to FIG. 1, the display device 1 includes a display area DAthat emits light and a non-display area NDA that does not emit light.The display device 1 may provide an image by using light emitted from aplurality of pixels arranged in the display area DA.

The display device 1 includes an opening area OA at least partiallysurrounded by the display area DA. FIG. 1 illustrates that the openingarea OA is entirely surrounded by the display area DA. The non-displayarea NDA may include a first non-display area NDA1 surrounding theopening area OA, and a second non-display area NDA2 surrounding thedisplay area DA. The first non-display area NDA1 may entirely surroundthe opening area OA, the display area DA may entirely surround the firstnon-display area NDA1, and the second non-display area NDA2 may entirelysurround the display area DA.

Although an organic light-emitting display device will now beillustrated and described as the display device 1, the display device 1is not limited thereto. According to another embodiment, various typesof display devices, such as an inorganic light-emitting display and aquantum dot light-emitting display, may be used.

FIGS. 2A to 2D are schematic cross-sectional views of the display device1 according to embodiments, and may correspond to cross-sections takenalong a line II-II′ of FIG. 1. The opening area OA is located betweentwo pixels. For example, the opening area OA is located between twoOLEDs.

Referring to FIG. 2A, the display device 1 may include a display panel10 and a component 20 corresponding to the opening area OA of thedisplay panel 10. Although not shown, an element (s) such as an inputsensing member for sensing a touch input, an anti-reflection memberincluding a polarizer and a retarder, or a color filter and a blackmatrix, and a transparent window may be arranged on the display panel10.

The display panel 10 may include a substrate 100, a display elementlayer 200 disposed on the substrate 100, and a thin-film encapsulationlayer 300 as an encapsulation member that covers the display elementlayer 200.

The substrate 100 may includes a glass material, polymer material, or ametal material. The substrate 100 may be rigid or flexible. For example,the substrate 100 may be a transparent glass substrate containing SiO₂as a main component, or a substrate including a polymer resin such asreinforced plastic. The display element layer 200 includes a pixelcircuit including a thin film transistor (TFT) arranged on the displayarea DA, and a display element, such as an organic light-emitting diode(OLED) electrically connected to the pixel circuit. The thin-filmencapsulation layer 300 may prevent external moisture or contaminatedmaterials from infiltrating into the display element layer 200, bycovering the display element layer 200. The thin-film encapsulationlayer 300 may include at least one inorganic encapsulation layer and atleast one organic encapsulation layer.

As shown in FIG. 2A, the display panel 10 may include an opening 10Hthat corresponds to the opening area OA and penetrates (e.g., completelypenetrates through) the display panel 10. The substrate 100, the displayelement layer 200, and the thin-film encapsulation layer 300 may includefirst through third openings 100H, 200H, and 300H corresponding to theopening area OA, respectively, and the first through third openings100H, 200H, and 300H may together form the opening 10H of the displaypanel 10. The first opening 100H may penetrate from a top surface to abottom surface of the substrate 100, the second opening 200H maypenetrate from a lowermost layer to an uppermost layer of the displayelement layer 200, and the third opening 300H may penetrate through thethin-film encapsulation layer 300.

The opening area OA is an area in which a component 20 is located (e.g.,at least a portion of the component 20 is laterally aligned with theopening 10H in the display panel 10). Although the component 20 isarranged below the substrate 100 in FIG. 2A, embodiments are not limitedthereto. According to another embodiment, as shown in FIG. 2B, thecomponent 20 may be arranged within the opening 10H such that at least aportion of the component 20 overlaps, in a thickness direction of thedisplay panel 10, a lateral surface of the display panel 10 that facesthe opening 10H (e.g., in one or more embodiments, at least a portion ofthe component may extend into the opening 10H in the display panel 10).

The component 20 may include an electronic element. For example, thecomponent 20 may be an electronic element that uses light or sounds. Forexample, the electronic element may include a sensor that emits and/orreceives and uses light, like an infrared sensor, a camera that receiveslight and captures an image, a sensor that outputs and senses light orsound to measure a distance or recognize a fingerprint or the like, asmall lamp that outputs light, or a speaker that outputs sound. Anelectronic element using light may use light in various wavelengthbands, such as visible light, infrared light, and ultraviolet light.According to some embodiments, the opening area OA may be understood asa transmission area capable of transmitting light or/and sound that isoutput from the component 20 to the outside or travels from the outsidetoward the component 20.

According to an embodiment, when the display panel 10 is used as a smartwatch or an instrument panel for automobiles, the component 20 may be amember including a needle of a clock or a needle or the like indicatingpredetermined information (e.g. a velocity of a vehicle, etc.). As shownin FIG. 2A or 2B, the component 20 is a component that may be arrangedat a location corresponding to the opening 10H of the display panel 10.As described above, the component 20 may include an element(s) relatedto a function of the display panel 10 or an element such as an accessorythat increases an esthetic sense of the display panel 10.

In FIGS. 2A and 2B, the substrate 100, the display element layer 200,and the thin-film encapsulation layer 300 include the first throughthird openings 100H, 200H, and 300H corresponding to the opening areaOA, respectively. However, as shown in FIG. 2C, the substrate 100 maynot include the first opening 100H.

Referring to FIG. 2C, although the substrate 100 does not include thefirst opening 100H, the display element layer 200 and the thin-filmencapsulation layer 300 may include the second and third openings 200Hand 300H, respectively. According to an embodiment, a lighttransmittance in the opening area OA of the display panel 10 shown inFIG. 2C may be about 50% or greater, 70% or greater, 75% or greater, 80%or greater, 85% or greater, or 90% or greater.

The component 20 is arranged in the opening area OA. As shown in a solidline of FIG. 2C, the component 20 may be arranged below the displaypanel 10 such that the component 20 does not overlap the lateral surfaceof the display panel 10 that faces the opening 10H, or as shown in adotted line of FIG. 2C, at least a portion of the component 20 may bearranged within the second and third openings 200H and 300H such thatthe component 20 overlaps, in a thickness direction of the displayelement layer 200 and the thin-film encapsulation layer 300, the lateralsurface of the display panel 10 that faces the opening 10H.

Referring to FIG. 2D, the substrate 100 and the thin-film encapsulationlayer 300 may not include the first opening 100H and the third opening300H, respectively, but the display element layer 200 may include thesecond opening 200H. Additionally, in the embodiment of FIG. 2D, thethin-film encapsulation layer 300 may include a recessed portion thatextends along the lateral surfaces of the display element layer 200facing the opening 10H and an upper surface of the substrate 100 facingthe opening 10H. In FIG. 2D, the component 20 is arranged in the openingarea OA such that the component 20 does not overlap the lateral surfaceof the display panel 10 that faces the opening 10H. However, thecomponent 20 may be arranged at the location indicated by the dottedline of FIG. 2C.

FIG. 3 is a schematic plan view of a display panel 10 according to anembodiment, and FIG. 4 is a circuit diagram of one of a plurality ofpixels of the display panel 10.

Referring to FIG. 3, the display panel 10 includes a plurality of pixelsP arranged in the display area DA. Each of the pixels P may include anOLED. Each of the pixels P may emit, for example, red light, greenlight, blue light, or white light, via the OLED.

Referring to FIG. 4, the pixel P includes a pixel circuit PC and an OLEDconnected to the pixel circuit PC. The pixel circuit PC may include afirst TFT T1, a second TFT T2, and a storage capacitor Cst.

The second TFT T2, which is a switching TFT, is connected to a scan lineSL and a data line DL, and transmits, to the first TFT T1, a datavoltage received via the data line DL according to a switching voltagereceived via the scan line SL. The storage capacitor Cst is connected tothe second TFT T2 and a driving voltage line PL, and stores a voltagecorresponding to a difference between a voltage received from the secondTFT T2 and a first power supply voltage ELVDD supplied to the drivingvoltage line PL.

The first TFT T1, which is a driving TFT, is connected to the drivingvoltage line PL and the storage capacitor Cst, and may control a drivingcurrent flowing from the driving voltage line PL to the OLED, inaccordance with a voltage value stored in the storage capacitor Cst. TheOLED may emit light having a certain brightness by the driving current.An opposite electrode (for example, a cathode) of the OLED may receive asecond power supply voltage ELVSS.

Although a case where the pixel circuit PC includes two TFTs and onestorage capacitor is illustrated in FIG. 4, embodiments are not limitedthereto. The number of TFTs and the number of storage capacitors mayvary according to a design of the pixel circuit PC.

Referring back to FIG. 3, the first non-display area NDA1 may surroundthe opening area OA. The first non-display area NDA1 is an area in whicha display element that emits light is not arranged. Wires, e.g., signallines, connected to the pixels P arranged around the opening area OA mayextend across the first non-display area NDA1, or a groove(s) describedbelow may be arranged in the first non-display area NDA1. In the secondnon-display area NDA2, a scan driver 1100 that provides a scan signal toeach of the pixels P, a data driver 1200 that provides a data signal toeach of the pixels P, and a main power wire (not shown) for providingfirst and second power supply voltages may be arranged.

FIG. 3 may be understood as a figure of the substrate 100 of the displaypanel 10. For example, the substrate 100 may be understood as includingthe opening area OA, the display area DA, and the first and secondnon-display areas NDA1 and NDA2.

FIG. 5 is a plan view of a portion of a display panel according to anembodiment and shows lines located in the first non-display area NDA1.

Referring to FIG. 5, pixels P may be arranged in the display area DAaround the opening area OA, and the first non-display area NDA1 may belocated between the opening area OA and the display area DA.

The pixels P may be spaced apart from each other around the opening areaOA. The pixels P may be vertically spaced apart from each other aroundthe opening area OA, or horizontally spaced apart from each other aroundthe opening area OA.

Signal lines adjacent to the opening area OA, from among signal linesthat supply signals to the pixels P, may detour around the opening areaOA. Some of the data lines DL that traverse the display area DA mayextend in a y direction to provide data signals to the pixels P arrangedvertically around the opening area OA, and may detour around the firstnon-display area NDA1 along an edge (e.g., an arc) of the opening areaOA. Some of the scan lines SL that traverse the display area DA mayextend in an x direction to provide scan signals to the pixels Parranged horizontally around the opening area OA, and may detour aroundthe first non-display area NDA1 along an edge (e.g., an arc) of theopening area OA.

FIG. 6 is a plan view of a portion of a display panel according to anembodiment and shows grooves located in the first non-display area NDA1.

Grooves are located between the opening area OA and the display area DA.The embodiment of FIG. 6 illustrates first and second grooves G1 and G2located between the opening area OA and the display area DA. However,according to another embodiment, only one groove or three or moregrooves may be arranged between the opening area OA and the display areaDA.

Each of the first and second grooves G1 and G2 may have a ring shapeentirely surrounding the opening area OA in the first non-display areaNDA1. In FIG. 6, because the opening area OA has a circular shape, thefirst and second grooves G1 and G2 are circular rings (e.g., in one ormore embodiments, the shape of the grooves G1 and G2 corresponds to theshape of the opening area OA). However, the opening area OA may be inthe shape of an oval or a polygon, and accordingly, each of the firstand second grooves G1 and G2 may also have any of various types of ringshapes. A diameter of each of the first and second grooves G1 and G2with respect to a center point of the opening area OA may be greaterthan a diameter of the opening area OA, and the first and second groovesG1 and G2 may be spaced apart from each other by an interval (e.g., agap) in the first non-display area NDA1.

FIG. 7 is a cross-sectional view of the display panel according to anembodiment, and corresponds to a cross-section taken along a lineVII-VII′ of FIG. 6. FIG. 8 is a enlarged cross-sectional view of an OLEDof FIG. 7. FIG. 9A is a cross-sectional view of the first groove G1, andFIG. 9B is a cross-sectional view illustrating a stacked structure onthe first groove G1 of FIG. 9A.

Referring to the display area DA of FIG. 7, the substrate 100 may be asubstrate including a glass material, polymer material or/and metalmaterial as described above.

A buffer layer 201 to prevent infiltration of impurities into asemiconductor layer of a TFT may be arranged on the substrate 100. Thebuffer layer 201 may include an inorganic insulating material, such assilicon nitride or silicon oxide, and may be a single layer or multiplelayers including the inorganic insulating material.

A pixel circuit PC including a TFT and a storage capacitor Cst may bearranged on the buffer layer 201. The TFT may include a semiconductorlayer ACT, a gate electrode GE, a source electrode SE, and a drainelectrode DE. The TFT of FIG. 7 may correspond to the driving TFT ofFIG. 4. According to the present embodiment, the TFT is a top gate typein which the gate electrode GE is arranged on the semiconductor layerACT with a gate insulating layer 203 therebetween. However, according toanother embodiment, the TFT may be a bottom gate type in which a gateelectrode is arranged below a gate insulating layer and a semiconductorlayer is arranged above the gate insulating layer.

The semiconductor layer ACT may include polysilicon. Alternatively, thesemiconductor layer ACT may include amorphous silicon, an oxidesemiconductor, or an organic semiconductor. The gate electrode GE2 mayinclude a low resistance metal material. The gate electrode GE mayinclude a conductive material including molybdenum (Mo), aluminum (Al),copper (Cu), and titanium (Ti), and may be formed as a multi-layer orsingle layer including the aforementioned materials.

The gate insulating layer 203 may be interposed between thesemiconductor layer ACT and the gate electrode GE and may include aninorganic insulating material, such as silicon oxide, silicon nitride,silicon oxynitride, aluminum oxide, titanium oxide, tantalum oxide, orhafnium oxide.

The source electrode SE and the drain electrode DE may include a highlyconductive material. Each of the source electrode SE and the drainelectrode DE may include a conductive material including Mo, Al, Cu, andTi, and may be a multi-layer or single layer including theaforementioned materials. According to an embodiment, each of the sourceelectrode SE and the drain electrode DE may be formed as a multi-layer(triple-layer) of Ti/Al/Ti.

The storage capacitor Cst includes a lower electrode CE1 and an upperelectrode CE2 with a first interlayer insulating layer 205 therebetween.The lower electrode CE1 and the upper electrode CE2 overlap each other.The storage capacitor Cst may be covered with a second interlayerinsulating layer 207.

The storage capacitor Cst may be overlapped with the TFT. FIG. 7illustrates a case where the gate electrode GE of the TFT is the lowerelectrode CE1 of the storage capacitor Cst, but the present disclosureis not limited thereto. According to another embodiment, the storagecapacitor Cst may not overlap with the TFT.

The first and second interlayer insulating layers 205 and 207 mayinclude an inorganic insulating material, such as silicon oxide, siliconnitride, silicon oxynitride, aluminum oxide, titanium oxide, tantalumoxide, or hafnium oxide, and may each be multi-layers or single layers.

The pixel circuit PC including the TFT and the storage capacitor Cst maybe covered with a planarization insulating layer 209. The planarizationinsulating layer 209 may be an organic insulating layer including acommercial polymer such as polymethyl methacrylate (PMMA) or polystyrene(PS), a polymer derivative having a phenol-based group, an acryl-basedpolymer, an imide-based polymer, an acryl ether-based polymer, anamide-based polymer, a fluorine-based polymer, a p-xylene-based polymer,a vinyl alcohol-based polymer, a blend thereof, or the like. Accordingto an embodiment, the planarization insulating layer 209 may includepolyimide.

The OLED may be arranged on the planarization insulating layer 209. Apixel electrode 221 of the OLED may be arranged on the planarizationinsulating layer 209 and may be connected to the pixel circuit PC via acontact hole of the planarization insulating layer 209.

The pixel electrode 221 may include conductive oxide, such as indium tinoxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide(In₂O₃), indium gallium oxide (IGO), or aluminum zinc oxide (AZO).According to another embodiment, the pixel electrode 221 may include areflection layer including silver (Ag), magnesium (Mg), aluminum (Al),platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd),iridium (Ir), chromium (Cr), or a compound of these materials. Accordingto another embodiment, the pixel electrode 221 may further include afilm formed of ITO, IZO, ZnO, or In₂O₃ above/below the reflection layer.

A pixel-defining layer 211 includes an opening via which an uppersurface of the pixel electrode 221 is exposed, and covers an edge of thepixel electrode 221. The pixel-defining layer 211 may include an organicinsulating material. The pixel-defining layer 211 may include theorganic insulating material described above in the above-description ofthe planarization insulating layer 209. The pixel-defining layer 211 mayinclude the organic insulating material and/or an inorganic insulatingmaterial. According to an embodiment, the pixel-defining 211 may includepolyimide.

An intermediate layer 222 of the OLED includes an emission layer. Theemission layer may include a low molecular or high molecular organicmaterial that emits light of a certain color. According to anembodiment, as shown in FIG. 8, the intermediate layer 222 may furtherinclude a first functional layer 222 a arranged below an emission layer222 b, and/or a second functional layer 222 c arranged above theemission layer 222 b.

The first functional layer 222 a may be a single layer or a multi-layer.For example, when the first functional layer 222 a is formed of a highmolecular weight material, the first functional layer 222 a is a holetransport layer (HTL) having a single-layer structure, and may be formedof poly-(3,4)-ethylene-dihydroxy thiophene (PEDOT) or polyaniline(PANI). On the other hand, when the first functional layer 222 a isformed of a low molecular weight material, the first functional layer222 a may include a hole injection (HIL) and an HTL.

The second functional layer 222 c is optional. For example, when thefirst functional layer 222 a and the emission layer 222 b are formed ofhigh molecular weight materials, the second functional layer 222 c maybe formed to improve the characteristics of the OLED. The secondfunctional layer 222 c may be a single layer or a multi-layer. Thesecond functional layer 222 c may include an electron transport layer(ETL), and/or an electron injection layer (EIL).

Some of a plurality of layers that constitute the intermediate layer222, for example, the first and second functional layers 222 a and 222c, may be arranged not only in the display area DA but also in the firstnon-display area NDA1, and may be disconnected in the first non-displayarea NDA1 by the first groove G1 and the second groove G2 describedbelow.

An opposite electrode 223 of the OLED may be arranged to face the pixelelectrode 221, with the intermediate layer 222 therebetween. Theopposite electrode 223 may be formed of a conductive material having alow work function. For example, the opposite electrode 223 may include a(semi)transparent layer including silver (Ag), magnesium (Mg), aluminum(Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium(Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca) or analloy of these materials. Alternatively, the opposite electrode 223 mayfurther include a layer, such as ITO, IZO, ZnO, or In₂O₃, on the(semi)transparent layer including any of the above-described materials.

The OLED is covered with the thin-film encapsulation layer 300. Thethin-film encapsulation layer 300 may include at least one organicencapsulation layer and at least one inorganic encapsulation layer.Although the thin-film encapsulation layer 300 includes first and secondinorganic encapsulation layers 310 and 330 and an organic encapsulationlayer 320 therebetween in FIG. 7, a stacking order of the first andsecond inorganic encapsulation layers 310 and 330 and the organicencapsulation layer 320 and the numbers of inorganic encapsulationlayers and organic encapsulation layers may be changed.

The first and second inorganic encapsulation layers 310 and 330 mayinclude an inorganic insulating material of at least one of aluminumoxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide,silicon oxide, silicon nitride, and silicon oxynitride, and may beformed via chemical vapor deposition (CVD) or the like. The organicencapsulation layer 320 may include a polymer-based material. Examplesof the polymer-based material may include acrylic resin, epoxy resin,polyimide, and polyethylene.

Referring to the first non-display area NDA1 of FIG. 7, the firstnon-display area NDA1 may include a first sub-non-display area SNDA1,which is distal to the opening area OA, and a second sub-non-displayarea SNDA2, is proximate to the opening area OA (e.g., the secondsub-non-display area SNDA2 is closer to the opening area OA than thefirst sub-non-display area SNDA1).

The first sub-non-display area SNDA1 is an area traversed by wires,e.g., the signal lines described above with reference to FIG. 5. FIG. 7illustrates data lines DL located in the first sub-non-display areaSNDA1. The data lines DL of FIG. 7 correspond to the data lines DL thatdetour around the opening area OA described with reference to FIG. 5.The data lines DL may be alternately arranged with an insulating layer(e.g., a second interlayer insulating layer) therebetween. In this case,a gap (a pitch) between adjacent data lines DL may be reduced and awidth of the first non-display area NDA1 may be reduced. According toanother embodiment, the data lines DL may be all arranged on the samelayer, for example, on the second interlayer insulating layer 207.

Although FIG. 7 shows the data lines DL located in the firstsub-non-display area SNDA1, the scan lines that detour the opening areaOA described with reference to FIG. 5 may be also located in the firstsub-non-display area SNDA1.

The second sub-non-display area SNDA2 may be an area in which the firstand second grooves G1 and G2 are arranged. The first and second groovesG1 and G2 are formed in a multi-layer ML arranged on the substrate 100.The multi-layer ML includes a lower insulating layer 250 and at leastone insulating layer AIL arranged on the lower insulating layer 250. Thelower insulating layer 250 may be interposed between the substrate 100and the pixel circuit PC, for example, between the substrate 100 and theTFT. The embodiment of FIG. 7 illustrates the lower insulating layer 250arranged directly on the substrate 100. The at least one insulatinglayer AIL may include an inorganic insulating layer. In the embodimentillustrated in FIG. 7, the at least one insulating layer AIL includesthe buffer layer 201, the gate insulating layer 203, the firstinterlayer insulating layer 205, and the second interlayer insulatinglayer 207. The at least one insulating layer AIL may refer to one ormore insulating layers selected from the buffer layer 201, the gateinsulating layer 203, the first interlayer insulating layer 205, and thesecond interlayer insulating layer 207.

The first and second grooves G1 and G2 may have certain depths in athickness direction of the multi-layer ML, and each of the first andsecond grooves G1 and G2 may have an undercut structure in which a widthof a portion of each of the first and second grooves G1 and G2 that passthrough the lower insulating layer 250 is greater than a width of aportion of each of the first and second grooves G1 and G2 that passesthrough the at least one insulating layer AIL. Like the at least oneinsulating layer AIL being an inorganic insulating layer and the lowerinsulating layer 250 being an organic insulating layer, the at least oneinsulating layer AIL and the lower insulating layer 250 may includedifferent materials from each other. The lower insulating layer 250 mayinclude, for example, polyimide.

Referring to FIG. 9A, a first width W1 of a portion of the first grooveG1 that penetrates through the lower insulating layer 250 in the depthdirection is greater than a second width W2 of a portion of the firstgroove G1 that penetrates through the at least one insulating layer AIL.A lateral surface of the at least one insulating layer AIL may protrudefurther toward a center of the first groove G1 than a lateral surface205IE of the lower insulating layer 250, and a protruding portion of theat least one insulating layer AIL may form a tip (or an eave) (e.g., alower surface of the at least one insulating layer AIL may overhang theportion of the first groove G1 in the lower insulating layer 250). FIG.9A illustrates a pair of tips (or eaves). The tip may protrude by about0.9 μm to about 1.2 μm in the x direction farther than the lateralsurface 250IE of the lower insulating layer 250.

The first groove G1 may be formed by etching the at least one insulatinglayer AIL and the lower insulating layer 250. An etchant or an etch gasthat is used during an etching process for removing a portion of the atleast one insulating layer AIL may include a different material from anetchant or an etch gas that is used during an etching process forremoving a portion of the lower insulating layer 250.

Via etching, a first hole 250 h may be formed in the lower insulatinglayer 250 and a second hole AIL-h may be formed in the at least oneinsulating layer AIL. The first hole 250 h and the second hole AIL-h maybe connected to each other (e.g., in communication with each other) toform the first groove G1. The first width W1 of the first hole 250 h isgreater than the second width W2 of the second hole AIL-h, and the firstgroove G1 may have an undercut structure in which a lower width isgreater than an upper width. FIG. 9A illustrates that a lateral surfaceAIL-IE of the at least one insulating layer AIL that defines the secondhole AIL-h protrudes by a first distance d1 toward the center of thefirst groove G1 in a lateral direction (x direction), farther than thelateral surface 205IE of the lower insulating layer 250 that defines thefirst hole 250 h. In the illustrated embodiment, the first hole 250 h offirst groove G1 that penetrates through the lower insulating layer 250may taper from a relatively wider end at an upper surface of the lowerinsulating layer 250 facing the at least one insulating layer AIL to arelatively narrower end at a lower surface of the lower insulating layer250 facing the substrate 100 (e.g., the lateral surface 250IE may taperfrom a relatively wider upper end to a relatively narrower lower end).Additionally, the width W1 may refer to the width of the relative widerupper end of the first hole 250 h at the upper surface of the lowerinsulating layer 250.

The first distance d1 may be less than a thickness t of the lowerinsulating layer 250, may be equal to the thickness t of the lowerinsulating layer 250, or may be greater than the thickness t of thelower insulating layer 250. The first distance d1 may be greater than athickness of the first inorganic encapsulation layer 310 or may begreater than a sum of respective thicknesses of the first and secondinorganic encapsulation layers 310 and 330. According to an embodiment,the first distance d1 may be equal to or greater than about 1 μm. Inother words, the tip may protrude by the first distance d1 farther thanthe lateral surface 205IE of the lower insulating layer 250 toward thecenter of the first groove G1.

After the first groove G1 is formed in the multi-layer ML as shown inFIG. 9A, the intermediate layer 222 and the opposite electrode 223 maybe formed via thermal deposition or the like. Some of the plurality oflayers that constitute the intermediate layer 222, for example, thefirst or/and second functional layers 222 a or/and 222 c, and theopposite electrode 223 may be formed on the substrate 100 viadeposition. At this time, the first and/or second functional layers 222a and/or 222 c and the opposite electrode 223 may each be disconnectedby the first groove G1 and the second groove G2 located in the firstnon-display area NDA1. FIG. 9B illustrates that the first and/or secondfunctional layers 222 a and/or 222 c of the intermediate layer 222 andthe opposite electrode 223 are each disconnected by the first groove G1.

Although FIGS. 9A and 9B have been described above by focusing on thefirst groove G1, the second groove G2 has the same structure as thefirst groove G1, and the first and/or second functional layer 222 aor/and 222 c and the opposite electrode 223 are each disconnected by thesecond groove G2, as described above.

Referring back to FIG. 7, the thin-film encapsulation layer 300 alsocovers the first non-display area NDA1. Because the first inorganicencapsulation layer 310 that is formed via CVD or the like has arelatively high step coverage in contrast with the intermediate layer222 and the opposite electrode 223, the first inorganic encapsulationlayer 310 may cover the entire respective inner surfaces of the firstand second grooves G1 and G2. As shown in FIG. 9B, the first inorganicencapsulation layer 310 may cover the lateral surface 205IE and a bottomsurface of the lower insulating layer 250 and the lateral surface AIL-IEand a bottom surface of the at least one insulating layer AIL. Thesesurfaces define the first groove G1. The bottom surface of the lowerinsulating layer 250 may correspond to an upper surface of the substrate100, and the bottom surface of the at least one insulating layer AIL maycorrespond to a lower surface of the buffer layer 201.

The first inorganic encapsulation layer 310 may cover the disconnectedfirst and second functional layers 222 a and 222 c and the disconnectedopposite electrode 233 located within the first and second grooves G1and G2 and may directly contact a portion of the upper surface of thesubstrate 100 exposed via the first groove G1. A thickness of the firstinorganic encapsulation layer 310, for example, a thickness thereof in adirection (z direction) perpendicular to the substrate 100, may be lessthan the thickness t of the lower insulating layer 250. A portion of thefirst groove G1 may be at least partially filled with the organicencapsulation layer 320 on the first inorganic encapsulation layer 310.

As illustrated in FIG. 7, the organic encapsulation layer 320 may covernot only the display area DA but also a portion of the first non-displayarea NDA1. For example, an end 320E of the organic encapsulation layer320 may be between the first groove G1 and the second groove G2. Theorganic encapsulation layer 320 may be formed by coating monomer or thelike on the substrate 100 and then hardening the coated monomer. Whenthe organic encapsulation layer 320 is exposed via the opening 10H,moisture may infiltrate via the organic encapsulation layer 320. Toaddress this problem, a portion of the organic encapsulation layer 320,for example, a portion thereof corresponding to an area HA between theopening area OA and the first groove G1, may be removed via ashingprocess or the like. Accordingly, as viewed in a direction perpendicularto the upper surface of the substrate 100, the area HA not including theorganic encapsulation layer 320 may be in the shape of a ring thatsurrounds the opening area OA, and the end 320E of the organicencapsulation layer 320 may be located between the first groove G1 andthe second groove G2.

As the end 320E of the organic encapsulation layer 320 is located closerto the display area DA than respective ends of the first and secondinorganic encapsulation layers 310 and 330, the first and secondinorganic encapsulation layers 310 and 330 may directly contact eachother in the area HA. The first and second inorganic encapsulationlayers 310 and 330 may directly contact each other in the second grooveG2 and around the opening 10H of the display panel 10.

An end 100E of the substrate 100 directed toward the opening 10H of thedisplay panel 10 may protrude further toward the opening 10H than an end250E of the lower insulating layer 250 directed toward the opening 10H.Although FIG. 7 illustrates a cross-section, as viewed in a directionperpendicular to the upper surface of the substrate 100 in both FIGS. 6and 7, like the substrate 100 including the first opening 100Hcorresponding to the opening area OA, the lower insulating layer 250 mayinclude an opening 250H corresponding to the opening area OA, and theopening 250H of the lower insulating layer 250 may have a greaterdiameter than the first opening 100H of the substrate 100.

The first opening 100H of the substrate 100 may be formed via lasercutting, drilling, etc. When an impact is applied to the at least oneinsulating layer AIL, which is an inorganic insulating layer, during aprocess of forming the first opening 100H, cracks may be generated, andforeign materials, such as external moisture, may infiltrate via thecracks of the at least one insulating layer AIL. However, when a portionof the multi-layer ML corresponding to the opening area OA is removedduring an etching process of forming the first and second grooves G1 andG2 and then the aforementioned laser cutting or drilling is performed toform the first opening 100H in the substrate 100, the formation ofcracks in the inorganic insulating layer may be prevented. A seconddistance d2 may be understood as a margin sufficient to prevent theinorganic insulating layer from cracking during laser cutting ordrilling. The second distance d2 is a distance between the end 100E ofthe substrate 100 and the end 250E of the lower insulating layer 250 andmay be about 0.1 μm or greater.

FIG. 10A is a cross-sectional view of a first groove G1 according toanother embodiment, and FIG. 10B is a cross-sectional view illustratinga stacked structure on the first groove G1 of FIG. 10A. Referring to theabove-described first groove G1 of FIGS. 9A and 9B, the lateral surfaceAIL-IE of the at least one insulating layer AIL is relatively flat. Onthe other hand, referring to FIGS. 10A and 10B, an undercut structure islocally formed in the at least one insulating layer AIL, and a lateralsurface of the at least one insulating layer AIL facing the first grooveG1 is uneven.

The at least one insulating layer AIL may include an inorganicinsulating layer, for example, a plurality of inorganic insulatinglayers including silicon element. Amounts by which the buffer layer 201,the gate insulating layer 203, the first interlayer insulating layer205, and the second interlayer insulating layer 207 are etched during anetching process may be different from each other according to variousconditions (e.g., the time, the composition of an etchant or etch gas,and the like) during the etching process and/or the respective materialsor the like included in the buffer layer 201, the gate insulating layer203, the first interlayer insulating layer 205, and the secondinterlayer insulating layer 207. For example, when the buffer layer 201and the first interlayer insulating layer 205 include silicon oxide andthe gate insulating layer 203 and the second interlayer insulating layer207 include silicon nitride, the amounts by which the buffer layer 201,the gate insulating layer 203, the first interlayer insulating layer205, and the second interlayer insulating layer 207 are etched may bedifferent from each other depending on the etching conditions (e.g.,time and the like) even when the same etching gas is used, as shown inFIG. 10A. A lateral surface 201IE of the buffer layer 201, a lateralsurface 203IE of the gate insulating layer 203, and a lateral surface2071E of the second interlayer insulating layer 207 may protrude furthertoward the center of the first groove G1 than a lateral surface 2051E ofthe first interlayer insulating layer 205 adjacent thereto and a lateralsurface 205IE of the lower insulating layer 250 adjacent thereto.Accordingly, a plurality of undercut structures may be formed in the atleast one insulating layer AIL such that the at least one insulatinglayer AIL has an uneven lateral surface facing the first groove G1. Theaforementioned uneven lateral surface of the first groove G1 is not justa concave and convex surface but is obtained as a plurality of inorganicinsulating layers included in the at least one insulating layer AIL hasdifferent materials from each other. Thus, the aforementioned unevenlateral surface may be understood as an uneven surface according to achange in a material in a thickness direction of the inorganicinsulating layers.

After the first groove G1 of FIG. 10A is formed, the intermediate layer222, for example, the first and second functional layers 222 a and 222c, and the opposite electrode 223 are formed via deposition and are eachdisconnected by the first groove G1, as described above with referenceto FIG. 9B. As described above with reference to FIG. 9B, the firstinorganic encapsulation layer 310 and the organic encapsulation layer320 are sequentially stacked on the opposite electrode 223.

FIG. 11 is a cross-sectional view of a display panel according toanother embodiment, and corresponds to the cross-section taken along theline VII-VII′ of FIG. 6. FIG. 12A is a cross-sectional view of a firstgroove G1 included in the display panel of FIG. 11, and FIG. 12B is across-sectional view illustrating a stacked structure on the firstgroove G1 of FIG. 12A. The display panel of FIGS. 11 through 12B issubstantially the same as the display panel of FIGS. 7 through 9B, andthus mainly a difference therebetween will now be described.

Referring to FIG. 11, first and second grooves G1 and G2 may be formedin the multi-layer ML, and bottom surfaces of the first and secondgrooves G1 and G2 may be on a virtual surface that is different from theupper surface of the substrate 100. For example, unlike the bottomsurfaces of the first and second grooves G1 and G2 of FIGS. 7 and 9Abeing arranged on the same virtual surface as the upper surface of thesubstrate 100, the bottom surfaces of the first and second grooves G1and G2 of FIGS. 11 and 12A may be on a virtual surface that is over(e.g., above) the upper surface of the substrate 100 and is also underan upper surface of the lower insulating layer 250.

Referring to FIG. 12A, the first groove G1 may be formed by etching themulti-layer ML. The second hole AIL-h penetrating through the at leastone insulating layer AIL may be formed by etching a portion of the atleast one insulating layer AIL, a first recess 250 r not penetratingentirely through the lower insulating layer 250 may be formed by etchinga portion of the lower insulating layer 250 (e.g., the first recess 250r may extend through only a portion of the lower insulating layer 250),and the first recess 250 r and the second hole AIL-h may together formthe first groove G1.

A depth h of the first recess 250 r may be less than the thickness t ofthe lower insulating layer 250. The depth h of the first recess 250 rmay be equal to or greater than 50%, 60%, 70%, 80%, 90%, 95%, or 97% ofthe thickness t of the lower insulating layer 250, but less than thethickness t of the lower insulating layer 250. The first recess 250 rand the second hole AIL-h may be connected to each other to form thefirst groove G1, and the bottom surface of the first groove G1 may be ona virtual surface in between the upper surface of the substrate 100 andthe upper surface of the lower insulating layer 250.

Because the lower insulating layer 250 is an organic insulating layer,when the lower insulating layer 250 remains below the first groove G1,there may exist a slight possibility that external moisture enters viathe remaining lower insulating layer 250 and flows into the OLED of FIG.11 via cracks of the inorganic insulating layer. However, when thesubstrate 100 is a rigid substrate as in an embodiment, there is a verylow possibility or no possibility that cracks are generated in theinorganic insulating layer stacked on the substrate 100, and thus theabove-described problem may be minimized.

When the intermediate layer 222, for example, the first and/or secondfunctional layer 222 a or/and 222 c, and the opposite electrode 223 areformed on the first groove G1 of FIG. 12A, the first and/or secondfunctional layer 222 a or/and 222 c and the opposite electrode 223 areeach disconnected by the first groove G1, as shown in FIG. 12B.

The structure of FIGS. 11 through 12B in which the first recess 250 rinstead of a first hole is formed in the lower insulating layer 250 isequally applicable to the structure of the first groove G1 describedabove with reference to FIGS. 10A and 10B and structures derivedtherefrom.

FIG. 13 is a cross-sectional view of a display panel according toanother embodiment.

The display panel of FIG. 13 has substantially the same structure as thedisplay panel of FIG. 7 except that a partition wall 400 is furtherincluded between the first groove G1 and the second groove G2.

The partition wall 400 may include an organic insulating material, andmay have a ring shape that surrounds the opening area OA, for example,the opening 10H, when viewed in a direction perpendicular to the uppersurface of the substrate 100. The partition wall 400 may include a firstsub-partition wall layer 410 including the same material as thatincluded in the planarization insulating layer 209, and a secondsub-partition wall layer 420 including the same material as thatincluded in the pixel defining layer 211. The partition wall 400 maycontrol the flow of the monomer during a process of forming the organicencapsulation layer 320.

The partition wall 400 of FIG. 13 may be included in the display panelhaving the first and second grooves G1 and G2 described above withreference to FIGS. 10A and 10B, the display panel having the first andsecond grooves G1 and G2 described above with reference to FIGS. 11through 12B, or various display panels derived from these displaypanels.

FIG. 14 is a cross-sectional view of a display panel according toanother embodiment, and corresponds to the cross-section taken along theline VII-VII′ of FIG. 6. FIG. 15A is a cross-sectional view of a firstgroove G1 of the display panel of FIG. 14, and FIG. 15B is across-sectional view illustrating a stacked structure on the firstgroove G1 of FIG. 15A. The display panel of FIG. 14 is substantially thesame as the display panel described above with reference to FIG. 7 andthe like except for a lower insulating layer 250′ and a structure offirst and second grooves G1 and G2 based on the lower insulating layer250′, and thus mainly the difference between the two display panels willnow be described.

The lower insulating layer 250′ in the display panel of FIG. 14 mayinclude an inorganic insulating layer. The lower insulating layer 250′may include an inorganic insulating layer that is different from the atleast one insulating layer AIL. For example, the lower insulating layer250′ may include silicon nitride or silicon oxycarbide (SiOC).

The first and second grooves G1 and G2 may each be formed by etching theat least one insulating layer AIL and the lower insulating layer 250′.An etchant or an etch gas that is used during a process of etching theat least one insulating layer AIL may be the same as or different froman etchant or an etch gas that is used during a process of etching thelower insulating layer 250′.

According to an embodiment, when the lower insulating layer 250′includes silicon nitride or silicon oxycarbide (SiOC), the buffer layer201, the gate insulating layer 203, and a lower second interlayerinsulating layer 207 a include silicon oxide, and the first interlayerinsulating layer 205 and an upper second interlayer insulating layer 207b include silicon nitride, the amounts by which these layers are etchedmay be different from each other as shown in FIG. 15A.

The lateral surfaces 201IE and 203IE of the buffer layer 201 and thegate insulating layer 203 directly on the lower insulating layer 250′may protrude further toward the center of the first groove G1 than alateral surface 250′IE of the lower insulating layer 250′, therebyforming an undercut structure. A lateral surface 207 aIE of the lowersecond interlayer insulating layer 207 a may protrude further toward thecenter of the first groove G1 than the lateral surface 2051E of thefirst interlayer insulating layer 205, thereby having an undercutstructure.

FIG. 15A illustrates a case where the second interlayer insulating layer207 is a multi-layer having different materials and thus the lateralsurfaces 207 aIE and 207 bIE of the upper and lower second interlayerinsulating layers 207 a and 207 b form a step, but embodiments are notlimited thereto. According to another embodiment, each of the bufferlayer 201, the gate insulating layer 203, and the first interlayerinsulating layer 205 may have a multi-layered structure having differentmaterials. In this case, the at least one insulating layer AIL maylocally have various shapes of undercut structures.

The lateral surface 250′IE of the lower insulating layer 250′, which isan inorganic insulating layer, may have a larger inclination angle of βthan an inclination angle of α of the lateral surface 205IE of the lowerinsulating layer 250, which is an organic insulating layer, as describedabove with reference to FIG. 9A. For example, the inclination angle of βof the lateral surface 250′IE of the lower insulating layer 250′ may be80° or greater or 85° or greater.

After the first groove G1 of FIG. 15A is formed, the intermediate layer222, for example, the first and second functional layers 222 a and 222c, and the opposite electrode 223 may be formed via deposition and mayeach be disconnected by the first groove G1. Thereafter, as describedabove with reference to FIGS. 7, 9B, and the like, the first inorganicencapsulation layer 310 and the organic encapsulation layer 320 aresequentially stacked on the opposite electrode 223.

FIG. 16 is a cross-sectional view of a display panel according toanother embodiment, and corresponds to the cross-section taken along theline VII-VII′ of FIG. 6. The display panel of FIG. 16 is substantiallythe same as the display panel of FIG. 14, and thus a differencetherebetween will now be mainly described.

Referring to FIG. 16, first and second grooves G1 and G2 may be formedin the multi-layer ML, and bottom surfaces of the first and secondgrooves G1 and G2 may be on a virtual surface that is different from theupper surface of the substrate 100. The bottom surfaces of the first andsecond grooves G1 and G2 of FIG. 14 are arranged on the same virtualsurface as the upper surface of the substrate 100, whereas the bottomsurfaces of the first and second grooves G1 and G2 of FIG. 16 may be ona virtual surface that is over (e.g. above) the upper surface of thesubstrate 100 and is also under an upper surface of the lower insulatinglayer 250′.

Portions of the first and second grooves G1 and G2 in the lowerinsulating layer 250′ are formed by partially etching the lowerinsulating layer 250′, and thus a recess may be formed in the lowerinsulating layer 250′ as described above with reference to FIG. 12A. Adepth h of the recess may be less than a thickness t of the lowerinsulating layer 250′. For example, the depth h of the recess of thelower insulating layer 250′ may be equal to or greater than 50%, 60%,70%, 80%, 90%, 95%, or 97% of the thickness t of the lower insulatinglayer 250′, but less than the thickness t of the lower insulating layer250′.

FIG. 17 is a schematic cross-sectional view of a display panel accordingto another embodiment. The display panel of FIG. 17 is substantially thesame as the display panel of FIG. 14, and thus mainly a differencetherebetween will now be described.

Referring to FIG. 17, the partition wall 400 may be between the firstgroove G1 and the second groove G2. The partition wall 400 includes thefirst and second sub-partition wall layers 410 and 420, and the materialthereof has been described above with reference to FIG. 13. Because thepartition wall 400 is able to control the flow of monomer duringformation of the organic encapsulation layer 320, an end of the organicencapsulation layer 320 formed as the monomer is hardened may bearranged adjacent to one lateral surface of the partition wall 400. Theend of the organic encapsulation layer 320 does not extend over thepartition wall 400 toward the opening 10H. The partition wall 400 ofFIG. 17 may also be included in the display panel of FIG. 16.

FIG. 18 is a plan view of a display panel 10′ according to anotherembodiment, and FIG. 19 is a plan view of the surroundings of an openingarea OA of FIG. 18. Descriptions of components and structures of thedisplay panel 10′ of FIG. 18 that are the same as those of the displaypanel 10 of FIGS. 3 through 6 will not be repeated, and differencesbetween the two display panels will now be focused on and described.

Referring to FIGS. 18 and 19, the opening area OA of the display panel10′ may be partially surrounded by the display area DA. Pixels P may bespaced apart from each other on left and right sides of the opening areaOA. Scan lines SL that transfer scan signals to pixels P on the leftside of the opening area OA and pixels P on the right side of theopening area OA may detour around the opening area OA in the firstnon-display area NDA1.

The opening area OA may be at least partially surrounded by the firstand second grooves G1 and G2. According to an embodiment, FIG. 19illustrates that the first groove G1 surrounds a portion of the openingarea OA (e.g., the first groove G1 partially surrounds the opening areaOA) and the second groove G2 entirely surrounds the entire opening areaOA. When the first groove G1 surrounds a portion of the opening area OA,both ends of the first groove G1 may be connected to a third groove G3located in the second non-display area NDA2. When the second groove G2entirely surrounds the entire opening area OA, the second groove G2 maybe connected to a fourth groove G4 located in the second non-displayarea NDA2. The third and fourth grooves G3 and G4 may extend along anedge of the substrate 100. Additionally, the third and fourth grooves G3and G4 may be parallel to each other.

FIG. 20 is a cross-sectional view taken along a line XX-XX′ of FIG. 18.

Referring to FIG. 20, scan lines SL located in the first sub-non-displayarea SNDA1 correspond to the scan lines SL that detour the opening areaOA described with reference to FIG. 19. In FIG. 20, the scan lines SLare alternately arranged with an insulating layer (e.g., the firstinterlayer insulating layer 205) therebetween. In this case, a pitchbetween the scan lines SL may be reduced. According to anotherembodiment, the scan lines SL may be arranged on the same insulatinglayer.

The second sub-non-display area SNDA2 includes the first and secondgrooves G1 and G2. Although FIG. 20 illustrates that a structure of thefirst and second grooves G1 and G2 and components around the first andsecond grooves G1 and G2 are the same as those described with referenceto FIG. 7, the second sub-non-display region SNDA2 may have a structureof the embodiment(s) described above with reference FIGS. 10A through 17and structures derived therefrom.

Although not shown in FIG. 20, the third and fourth grooves G3 and G4may have substantially the same cross-sectional structures as those ofthe first and second grooves G1 and G2. For example, each of the thirdand fourth grooves G3 and G4 may be formed to penetrate through the atleast one insulating layer AIL and the lower insulating layer 250,thereby having an undercut structure.

FIG. 21 is a plan view of a display panel 10″ according to anotherembodiment, and FIG. 22 is a plan view of surroundings of an openingarea OA of FIG. 21. Descriptions of components and structures of thedisplay panel 10″ of FIG. 21 that are the same as those of the displaypanel 10 of FIGS. 3 through 6 will not be repeated, and differencestherebetween will now be focused on and described.

Referring to FIGS. 21 and 22, the opening area OA of the display panel10′ may be partially surrounded by the display area DA. Pixels P may bespaced apart from each other on upper and lower sides of the openingarea OA. Scan lines SL that transfer scan signals to pixels P on theupper side of the opening area OA and pixels P on the lower side of theopening area OA may detour around the opening area OA in the firstnon-display area NDA1.

The opening area OA may be at least partially surrounded by the firstand second grooves G1 and G2. According to the embodiment illustrated inFIG. 22, the first groove G1 surrounds a portion of the opening area OA(e.g., the first groove G1 partially surrounds the opening area OA) andthe second groove G2 entirely surrounds the entire opening area OA. Whenthe first groove G1 surrounds a portion of the opening area OA, bothends of the first groove G1 may be connected to a third groove G3located in the second non-display area NDA2. When the second groove G2surrounds the entire opening area OA, the second groove G2 may beconnected to a fourth groove G4 located in the second non-display areaNDA2. The third and fourth grooves G3 and G4 may extend along an edge ofthe substrate 100. Additionally, the third and fourth grooves G3 and G4may be parallel to each other.

FIG. 23 is a cross-sectional view taken along a line XXIII-XXIII′ ofFIG. 22.

Referring to FIG. 23, data lines DL located in the first sub-non-displayarea SNDA1 correspond to data lines that detour the opening area OAdescribed with reference to FIG. 22. The second sub-non-display areaSNDA2 includes the first and second grooves G1 and G2. Although astructure of the second sub-non-display area SNDA2 of FIG. 22 is thesame as that described above with reference to FIG. 7, embodiments arenot limited thereto. According to another embodiment, the secondsub-non-display region SNDA2 may have the structure of the embodiment(s)described above with reference to FIGS. 10A through 17 and structuresderived therefrom.

Although not shown in FIG. 23, the third and fourth grooves G3 and G4may have substantially the same cross-sectional structures as those ofthe first and second grooves G1 and G2. For example, each of the thirdand fourth grooves G3 and G4 may be formed to penetrate through the atleast one insulating layer AIL and the lower insulating layer 250,thereby having an undercut structure.

According to embodiments, a multi-layer is on a substrate, and a groovemay be formed in the multi-layer including at least one insulating layerand a lower insulating layer. The groove can be formed regardless of amaterial of the substrate and may effectively block and preventinfiltration of moisture in a lateral direction. In one or moreembodiments, in a display panel including a substrate that includesglass, polymer, or metal, because a groove having an undercut structuremay be formed without removing the substrate, a material used to formthe substrate may not be limited. However, the aforementioned effectsare exemplary.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope as defined by the following claims.

What is claimed is:
 1. A display panel comprising: a glass substratecomprising an opening area, and a display area at least partiallysurrounding the opening area; a thin film transistor on the display areaand comprising a semiconductor layer and a gate electrode; a displayelement electrically connected to the thin film transistor; amulti-layer comprising at least one insulating layer and a lowerinsulating layer, wherein the at least one insulating layer is betweenthe glass substrate and the display element and the lower insulatinglayer is between the glass substrate and the at least one insulatinglayer; and a thin-film encapsulation layer covering the display elementand comprising at least one inorganic encapsulation layer and at leastone organic encapsulation layer, wherein the multi-layer comprises afirst groove located between the opening area and the display area, andwherein a first width of a portion of the first groove in the lowerinsulating layer is greater than a second width of a portion of thefirst groove in the at least one insulating layer.
 2. The display panelof claim 1, wherein a bottom surface of the first groove is on a virtualsurface between an upper surface of the lower insulating layer and anupper surface of the glass substrate or on a same virtual surface as theupper surface of the glass substrate.
 3. The display panel of claim 1,wherein the at least one insulating layer comprises a first holecorresponding to the first groove, and the lower insulating layercomprises a second hole or a recess corresponding to the first groove.4. The display panel of claim 3, wherein a lateral surface of the atleast one insulating layer facing a center of the first groove is closerto the center of the first groove than a lateral surface of the lowerinsulating layer facing the center of the first groove.
 5. The displaypanel of claim 1, wherein the lower insulating layer is in directcontact with an upper surface of the glass substrate.
 6. The displaypanel of claim 1, wherein the at least one inorganic encapsulation layercovers an inner surface of the first groove.
 7. The display panel ofclaim 1, wherein a portion of the at least one inorganic encapsulationlayer is in direct contact with a portion of the glass substrate withinthe first groove.
 8. The display panel of claim 1, wherein the glasssubstrate comprises a first opening corresponding to the opening area.9. The display panel of claim 8, wherein an end of the glass substratethat defines the first opening is closer to a center of the opening areathan an end of the lower insulating layer facing the opening area. 10.The display panel of claim 1, wherein the multi-layer further comprisesa second groove between the first groove and the opening area.
 11. Thedisplay panel of claim 10, wherein an end of the at least one organicencapsulation layer is between the first groove and the second groove.12. The display panel of claim 10, further comprising a partition wallon the multi-layer and located between the first groove and the secondgroove.
 13. The display panel of claim 1, wherein the lower insulatinglayer comprises an organic insulating layer and the at least oneinsulating layer comprises an inorganic insulating layer.
 14. Thedisplay panel of claim 1, wherein the lower insulating layer comprisesat least one of silicon nitride and silicon oxycarbide, and the at leastone insulating layer comprises an inorganic insulating layer thatcomprises a different material from the lower insulating layer.
 15. Adisplay device comprising: a substrate comprising an opening; a thinfilm transistor on a display area of the substrate, the display area atleast partially surrounding the opening, and comprising a semiconductorlayer and a gate electrode; a display element electrically connected tothe thin film transistor; a multi-layer comprising a lower insulatinglayer and at least one insulating layer, wherein the lower insulatinglayer is located on the substrate and the at least one insulating layeris located on the lower insulating layer and comprises a differentmaterial from the lower insulating layer; and an encapsulation layerconfigured to cover the display element, wherein the multi-layercomprises a first groove that is concave in a depth direction of themulti-layer, and a width of a portion of the first groove in the lowerinsulating layer is greater than a width of a portion of the firstgroove in the at least one insulating layer.
 16. The display device ofclaim 15, wherein the substrate comprises a glass material, a polymermaterial, or a metal material.
 17. The display device of claim 15,wherein a bottom surface of the first groove is on a virtual surfacebetween an upper surface of the lower insulating layer and an uppersurface of the substrate or on a same virtual surface as the uppersurface of the substrate.
 18. The display device of claim 15, whereinthe at least one insulating layer comprises a first hole correspondingto the first groove, and the lower insulating layer comprises a secondhole or a recess corresponding to the first groove.
 19. The displaydevice of claim 15, wherein the at least one insulating layer comprisesan inorganic insulating layer.
 20. The display device of claim 19,wherein the lower insulating layer comprises an organic insulating layeror comprises an inorganic insulating layer that is different from the atleast one insulating layer.
 21. The display device of claim 15, whereina lateral surface of the at least one insulating layer directed toward acenter of the first groove protrudes farther than a lateral surface ofthe lower insulating layer directed toward the center of the firstgroove.
 22. The display device of claim 15, wherein an end of thesubstrate directed toward the opening protrudes toward the openingfarther than an end of the lower insulating layer directed toward theopening.
 23. The display device of claim 15, wherein the multi-layerfurther comprises a second groove between the first groove and theopening.
 24. The display device of claim 23, wherein the encapsulationlayer comprises at least one inorganic encapsulation layer and at leastone organic encapsulation layer, and the at least one inorganicencapsulation layer covers an inner surface of each of the first grooveand the second groove.
 25. The display device of claim 24, wherein aportion of the at least one organic encapsulation layer at leastpartially fills the first groove.
 26. The display device of claim 25,further comprising a partition wall on the multi-layer and locatedbetween the first groove and the second groove.
 27. The display deviceof claim 24, wherein the at least one inorganic encapsulation layer isin direct contact with an upper surface of the substrate within thefirst groove or the second groove.
 28. The display device of claim 15,wherein the at least one insulating layer comprises a first insulatinglayer and a second insulating layer on the first insulating layer, thefirst and second insulating layers comprising different materials; andthe first insulating layer and the second insulating layer compriseholes corresponding to the first groove, respectively, and a width ofthe hole of the second insulating layer is less than a width of the holeof the first insulating layer.
 29. The display device of claim 15,wherein the display element comprises an organic light-emitting diode.30. The display device of claim 29, wherein at least one of an organiclayer and an opposite electrode included in the organic light-emittingdiode is disconnected by the first groove.